1. Field of the Invention
The present invention relates to reading data from an optical disc and recording data onto the optical disc, and more particularly, to methods of establishing a backup of each record information simultaneously when recording the record information onto the optical disc, and utilizing the backup record information to read the optical disc or record to the optical disc continuously when normally reading the record information from the optical disc fails.
2. Description of the Prior Art
Write-once discs belong to disc types capable of merely recording data once. That is, to delete a pre-recorded data from the write-once disc in order to record new data is unfeasible. For the above-mentioned reason, every time before a record operation is started, both a position of a latest closed session and a present status of the write-once disc indicating that it is not finalized need to be checked respectively for recording a new session continuously without overwriting or damaging the pre-recorded data on the write-once disc.
Please refer to FIG. 1. FIG. 1 is a flowchart illustrating a conventional loading operation of the write-once disc according to the prior art. In Step 1, the write-once disc is loaded into an optical disc drive and the optical disc drive reads data within a lead-in area for identifying that the type of the loaded optical disc is actually a write-once disc. In Step 2, the optical disc drive sequentially reads data stored in a plurality of control data corresponding to respective sessions on the write-once disc. In Step 3, the optical disc drive reads major record information of the write-once disc. The major record information is stored in several areas including Table of Content (TOC) areas, Session Disc Control Blocks (SDCBs), and Control Data (CD) areas, etc. The major record information stores total amount, positions, lengths, and status of sessions/fragments and physical format information of the write-once disc, and the major record information therefore affects a following recording operation of the write-once disc. When reading of the above-mentioned major record information fails, causing the identification of position and status of a closed session by previous recording is not possible the optical disc drive then performs Step 4. In Step 4, the optical disc drive determines that the loaded optical disc is finalized and thus recording new sessions onto the write-once disc is unfeasible. On the other hand, when the reading operation in Step 3 is successful, the flow will proceed to Step 5. In Step 5, the optical disc drive checks the position and the status of the latest closed session on the write-once disc through the latest data included in the major record information. The operation in Step 5 is implemented as a preparation for following recording or for setting the write-once disc as finalized. In Step 6, the optical disc drive keeps reading other data stored in the lead-in area on the write-once disc. In Step 7, the loading flow of the write-once disc is completed.
The conventional recording operation therefore takes a reading result of the major record information within the lead-in area on the write-once disc as a necessary condition for execution. However, in a conventional loading operation of the write-once disc, there is no backup of the major record information in other areas on the write-once disc. When demand for multi-times continuous recording occurs or when the write-once disc is damaged or scratched, the recording quality at this time is not stable, resulting in reading failure of the major record information. The optical disc drive is therefore unable to check the position and status of the latest closed session and fails to record new data onto the write-once disc continuously even though there is still storage space available for recording data. This wastes storage space on the write-once disc. From the above description, solving the recording problems due to reading failure of the major record information of the write-once disc is an important issue.